Israeli and Palestinian leaders are in Washington trying to make peace - again. This summit marks the latest chapter in a story that began on the White House lawn 17 years ago, when Israelis and Palestinians committed themselves to ending the conflict once and for all. Since then, every round has failed and bloodshed has continued. Against the backdrop of Tuesday's Palestinian terrorist attack that left four Israeli civilians dead, including a pregnant woman, why should these negotiations be different? Is there any reason for optimism? Indeed, there is. For the first time in history, most Arab leaders view a Middle Eastern state other than Israel - Iran - as their major enemy. The Israeli government under Prime Minister Binyamin Netanyahu is strong, stable and deeply committed to resolving the conflict based on two states for two peoples.

In the West Bank, Palestinian Authority President Mahmoud Abbas is working to restore law, order and economic prosperity while similarly pledging to pursue the two-state solution. And President Barack Obama has placed achieving peace at the top of his foreign-policy agenda. Never before, perhaps, have conditions been so conducive.

Still, daunting obstacles remain. Nearly half of the territory slated to become part of a Palestinian state is controlled by Hamas, an Iranian-backed terrorist group dedicated to Israel's destruction.

The Palestinian Authority, meanwhile, is insisting that Israel freeze all construction in West Bank Jewish communities indefinitely. While little can be done at this stage to neutralize the Hamas threat - the hope is that the people of Gaza will someday rid themselves of Hamas and opt for peace - the construction issue need not be a deal breaker. Adding a bedroom for a growing family should not disrupt the peace process.

THE WEST Bank - or, as the Bible calls it, Judea and Samaria - was twice used as a staging ground for wars of annihilation against Israel, which captured the area in 1967.

Sacred to the Jewish people for 3,000 years and vital to the defense of Israel's borders (which were a mere eight miles wide prior to 1967), the West Bank became home to hundreds of thousands of Israelis. With the start of the peace process in 1993, successive Israeli governments recognized the need to make painful sacrifices in these territories while upholding the right of Israeli citizens to continue building there. Palestinian and Israeli leaders agreed that the final status of these settlements would be determined, along with Jerusalem, refugees and borders, in the peace talks.

Since assuming office a year and a half ago, Netanyahu has made several gestures to the Palestinians to encourage them to return to the negotiating table. In addition to removing hundreds of checkpoints and facilitating the Palestinian economic boom, he has refrained from building any new settlements, from acquiring new territory for existing ones and from offering Israelis incentives to move to them. Finally, in a measure described as "unprecedented" by Secretary of State Hillary Clinton, Netanyahu froze all new construction within the settlements for a 10- month period.

The Palestinians are now threatening to quit the negotiations unless Netanyahu extends the construction freeze. Israel, of course, is seeking specific goals in the talks, including demilitarization of the Palestinian state and its recognition of Israel as the nation of the Jewish people. Israel also wants the Palestinians to cease teaching their children that Israel has no right to exist, and naming public squares after terrorists. But we are not insisting that the Palestinians meet these objectives before the talks even begin. We appreciate, therefore, Secretary Clinton's call for "good faith" negotiations "without preconditions."

Settlements have never been an obstacle to peace.

Though Israelis account for 17 percent of the West Bank's population, they inhabit a mere 1.7% of the land. The existence of the settlements did not prevent Egypt and Jordan from making peace with Israel, or the Palestinians from negotiating with us for nearly two decades. All parties to negotiations understand that the large settlement clusters will, in any final-status treaty, remain part of Israel.

As President Obama launches the direct Israeli-Palestinian talks, there is indeed reason for optimism, in spite of the obstacles. If the core issues are determined at the table rather than before negotiations start, Prime Minister Netanyahu and President Abbas can move swiftly and confidently toward concluding an historic treaty. Though long overdue, the peace we have yearned for may yet be achieved.